With the Beatles secluded at Abbey Road Studios, the artistic growth that had characterised their work in 1965's Rubber Soul continued at an accelerated pace. Revolver (1966) plumbed depths of emotional expression ("Eleanor Rigby") and technical expertise ("Tomorrow Never Knows") unprecendented in modern popular music. The landmark Sgt. Pepper's Lonely Hearts Club Band (1967), with its aural illusions and extensive use of unusual instruments and sounds, represented a new pinnacle in the colouristic and imaginative aspects of recorded music.
With the sprawling White Album (1968), a new Beatles emerged, one completely unfettered by the expectations of the listening public. This impression, suggested by the eight minute abstract sound collage "Revolution 9", was soon confirmed by Beatles' solo projects. The individual Beatles were no longer content to submerge their personalities for the benefit of the the whole. The Fabs, which John had once called "four parts of the same person", had begun to disintegrate.
The jetset elite had introduced them to psychoactive drugs - marijuana via Bob Dylan in 1964, LSD via their dentist in early 1965 - which they had embraced as both an escape from and a transcendence of, what they had become. Searching for a sense of purpose higher than their music, they became momentary disciples of the Maharishi Mahesh Yogi in 1967, which alienated them further from the mainstream audience. Brian Epstein who had struggled to keep them out of controversy, now watched in resignation as his boys grew facial hair, admitted to taking acid and announced their opposition to US involvement in Vietnam. As the group spent more time involved in esoteric persuits and less in maintaining their public image, Epstein's life, once dedicated to the Fab Four, became increasingly insular and chaotic. On 27 August, 1967, he died of an accidental overdose of barbituates.
Epstein's death was the beginning of the end of the Beatles. They never recovered from the loss of the man whose faith and vision had been the driving force behind their fame. Bravely, perhaps foolishly, they decided to manage themselves. When their first independent movie, the self-produced and directed TV film Magical Mystery Tour, proved frivolous and self-indulgent, it became evident - for the first time - that the Beatles weren't infalliable.
Finding their earnings subject to a 90% tax rate, the Beatles decided to invest their income in an entertainment conglomerate which they named Apple Corps Ltd. The company, which Paul dubbed an exercise in "Western communism" on 15 May, 1968, broadcast on the Tonight Show, was their statement to the mainstream world about the proper relationship between art and commerce. Apple was a place where artists of all styles and media could present and obtain a stable of old friends and young up-comers to Apple Records, bought scripts for Apple films, opened an Apple Boutique and solicited projects in newspaper advertisments. After a short time, however, the organisation was over-run with pretenders and hangers on. In desperation, the Beatles hired the Rolling Stones' former manager, Allen Klein, to pare down Apple's operations and personnel to bare essentials.
Despite the optimism that surrounded the post Sgt. Pepper era, the Beatles' artistic vision became increasingly less focused, their business affairs a tangle of greed and naïvete and their personal affairs alarmingly complex. John's all consuming relationship with his second wife Yoko Ono and Paul's with his wife Linda Eastman, effectively ended the association between the principal Beatles. In addition, George had long since tired of being a Beatle and was eager to move beyond the shadows of Lennon and McCartney. At the dawn of 1969, entering into what would become a seventeen month effort to make the Let It Be album and film, the Fab Four found themselves unwilling to continue to fulfill the role of the world's most celebrated entertainers. By the end of 1970, Paul McCartney found it necessary to sue his partners in order to avoid having his affairs managed by Klein, the man chosen by the other three Beatles.